Gilchrist himself played in the first ever T20 international in February 2005, at Auckland's Eden Park, when it was seen as nothing more than a sideshow.

Australian and New Zealand players dressed in retro gear - the Kiwis even sported handlebar moustaches and Aussie paceman Glenn McGrath took to bowling underarm at one point.

"I've got to be totally honest and say I was almost sceptical of the concept when it first came about," Gilchrist told Australian Regional Media.

New Zealand's Hamish Marshall during the International Twenty20 game played between the New Zealand Black Caps and Australia at Eden Park on February 17, 2005 in Auckland

"I just think because cricket had tried a lot of modified formats (and) each of those previous concepts like six-a-side, Super 8s, things like that, it seemed to compromise the game of cricket too much.

"It meant that it was a big hit and giggle, (and) much more heavily weighted to batting than bowling.

"That could be said of T20. But I think T20 has proven it is still a legitimate format of the game, and there's still high level of skill required to be good at it, but also a great deal of tactical nous and awareness."

Almost built for the game with his swashbuckling style of batting, Gilchrist would later play in the first T20 international on English soil during the memorable 2005 Ashes tour.

"They'd been playing it in county cricket for a few years - they got 180," Gilchrist recalled.

"We just thought '20 overs, you've got to go as hard as you can from the start'. I think we got bowled out for about 70.

"Players have learnt, and viewers have learnt too, that it's not just helter skelter, wild recklessness.

"There is skill and planning that goes into it."

Adam Gilchrist of Australia hits out during the Twenty20 Cup Super Eights match between Australia and Bangladesh at Newlands Cricket Ground on September 16, 2007 in Cape Town, South Africa.

Players - both batsmen and bowlers - have mastered their craft, or resculpted it to suit the needs of such a compact display, with innovative hitting and varying deliveries.

And slowly but surely, T20 has been winning over the traditionalists and staunch Test cricket supporters who were originally dead against further change.

Some were probably still coming to terms with the introduction of 50-overs-a-side "one-dayers".

"I think it is winning over more and more traditionalists because I think they're learning not to ... try to compare T20 cricket to Test cricket and even one-day cricket," said Gilchrist, who played 13 T20Is for Australia in addition to 96 Tests and 287 ODIs.

"They are three different formats and I believe they can all co-exist.

"The question really is just the volume, that's the big thing that needs to be closely monitored."

But as Gilchrist says, perhaps most significantly, T20 cricket - where games are done and dusted in three to four hours - is providing a "really entertaining package that is bringing new people to the game, and that's important to keep cricket healthy across the world".

Shane Warne was an early drawcard in the Big Bash League as captain of the Melbourne Stars.

While T20 has become the new poster child for cricket - and the World T20 championship tournament, rolled out every two years, is a popular addition to the international calendar - it is on the domestic scene that the game has really flourished and captured the imagination of fans, both old and new.

The Indian Premier League was the forebearer, but Australia's Big Bash League has become a raging success and given the public a chance to get behind a team in the same way they might an NRL, AFL or A-League club.

The state-based Sheffield Shield and domestic one-day tournaments - in their various forms - never drew in fans like the BBL has done.

Introduced in 2011-12, it has gone from strength to strength.

"Cricket Australia, while under siege from other angles at the moment, has done a great job," Gilchrist said.

"They were very patient with Twenty20 cricket.

"They observed the various nations around the world that had jumped into it quickly, watched with interest and learnt from those various tournaments and concepts, and I think they came up with a really engaging competition.

"The way the fans can engage in supporting a team, support individuals ... kids really warm to get their attention; merchandising and the mascots; fireworks - it's all there, it is entertainment."

Usman Khawaja hits out for the Sydney Thunder during its BBL final against the Melbourne Stars at the MCG last January.

In the last season of the state-based T20 Big Bash, in 201`0-11, an average 17,750 fans attended each match. It grew to 18,021 in the first year of the city-based Big Bash in 2011-12.

Last year, however, it ballooned to 29,443 per match, meaning the BBL joined the top 10 of the most attended sports leagues in the world.

A crowd of 80,883 alone attended the first of two Melbourne derbies between the Stars and Renegades at the MCG.

"Because of that tribal following - for want of a better term - that's why it's really well suited to domestic cricket," Gilchrist said.

"The world T20 tournaments are interesting - it's great seeing the countries go hard representing their nation, but I think it (T20) really lends itself to this type of concept where there is a mix of international players in with domestic players in a league format.

"At domestic level is where it's at its best."

Gilchrist, who retired from international cricket in 2008 before ending his career playing T20s with Middlesex in England and Kings XI Punjab in India, is an integral member of the commentary team for Ten, which in 2013 paid $100 million for the BBL rights over five years.

Kevin Pietersen bats for the Melbourne Stars. The former England star will again be a headline act of 2016-17.

The 2015-16 season attracted an average audience of 1.13 million in Australia - an 18% increase on the previous season - with the final between the Sydney Thunder and the Stars peaking at 2.24 million.

Earlier this year BBL boss Anthony Everard flagged the prospect of expanding the eight-team competition when the current TV rights deal expires in 2018.

Gilchrist, though, has warned against pushing too hard too early - as he sees it, you can have too much of a good thing.

"We've seen it grow over five BBLs ... whether it's attending matches or viewing on TV," he said.

"This year will be another big test to see if that continues or if it plateaus. That will give an indication of whether there is an appetite for more games or less.

"I'd be reluctant to rush into expansion of team numbers though. A lot of the various sporting codes have gone bad quickly, caused more damage later on down the track."